396 
dp 
It may be further pointed out that the value of = at this contact 
does not in general become infinitely great. This would be the case, 
if in the point of contact also the condition: 
Nema DEM 
EG — TL, San Vil, 
— 0°) 
was satisfied. 
It is easy to see from fig. 1 that this will not be the case in the 
point A. 
4. In $3 we assumed a very decided relative displacement of the 
fluid line with respect to the longitudinal plait for the derivation of 
fig. 2. It will be clear that the relative displacement of the said 
binodal curves can also take place in another way than that described 
above. If we want to ascertain how great the number of possibilities 
is that may occur, we should first of all bear in mind that our first 
dp kig 5 
assumption was, that (72) wen positive on the y-surface. Further 
we took the first component as solid substance. If we now exclude 
dp NP at 
the appearance of a line i = 0, it will be clear that we can 
cv 
kn dp AY, 
survey all the cases if we take | — | always positive, and choose 
ae / 
: A 
the two components as solid substances. For if {| — | is negative, 
Av Eh 
and the solid substance is the second component, we get the same 
dp\ . ne 
phenomena as in the case where | — | is positive, and the first 
RENE 
component appears as solid phase. 
oe dp a Nee 
So if we keep aa always positive, the situation of the longitu- 
av v 
dinal plait is always as indicated in figure 1. The differences between 
the cases which may occur, are accordingly caused by the fact that 
both components can occur as solid phase, and by the relative 
displacement of the solid-fluid line with respect to the longitudinal 
plait. 
If we confine ourselves to the case that the first component is the 
solid phase, we see a second possibility in figure 1, 1f we suppose 
: _ dp 
1) The transformed denominator of the above expression for — 
dat 
